I removed the radiator from my 1973 4/4 2 seater last year to have the top filler cap inlet renewed and also repositioned to enable the fitting of an overflow tank to the system.
The only way was down and out. I had to loosen the right hand side bracket at the bottom and pivot it away from the radiator path. After that a lot of jiggering and it just dropped out and into my hands. It also took more jiggering to refit and lots of patience.
Have a go and good luck.
A helper would also make the job much easier to.
